Explorer 1: The Beginning of American Space Science

Sixty
years ago next week, the hopes of Cold War America soared into the night sky as
a rocket lofted skyward above Cape Canaveral, a soon-to-be-famous barrier
island off the Florida coast.

The
date was Jan. 31, 1958. NASA had yet to be formed, and the honor of this first
flight belonged to the U.S. Army. The rocket's sole payload was a
javelin-shaped satellite built by the Jet Propulsion Laboratory in Pasadena,
California. Explorer 1, as it would soon come to be called, was America's first
satellite.

Against the backdrop of the 1950s Cold War, after the Soviet Union successfully launched Sputnik, Americans were determined to launch their own Earth-orbiting satellite. Flash back to events leading up to the successful launch of America's Explorer 1, and the beginnings of America's Space Age, as told through newsreel and documentary clips of the time.

"The launch of
Explorer 1 marked the beginning of U.S. spaceflight, as well as the scientific
exploration of space, which led to a series of bold missions that have opened
humanity's eyes to new wonders of the solar system," said Michael Watkins,
current director of JPL. "It was a watershed moment for the nation that
also defined who we are at JPL."

In the mid-1950s, both the
United States and the Soviet Union were proceeding toward the capability to put
a spacecraft in orbit. Yet great uncertainty hung over the pursuit. As the Cold
War between the two countries deepened, it had not yet been determined whether
the sovereignty of a nation's borders extended upward into space. Accordingly,
then-President Eisenhower sought to ensure that the first American satellites
were not perceived to be military or national security assets.

In 1954, an international
council of scientists called for artificial satellites to be orbited as part of
a worldwide science program called the International Geophysical Year (IGY),
set to take place from July 1957 to December 1958. Both the American and Soviet
governments seized on the idea, announcing they would launch spacecraft as part
of the effort. Soon, a competition began between the Army, Air Force and Navy
to develop a U.S. satellite and launch vehicle capable of reaching orbit.

At that time, JPL, which
was part of the California Institute of Technology in Pasadena, primarily
performed defense work for the Army. (The "jet" in JPL's name traces
back to rocket motors used to provide "jet assisted" takeoff for Army
planes during World War II.) In 1954, the laboratory's engineers began working
with the Army Ballistic Missile Agency in Alabama on a project called
"Orbiter." The Army team included Wernher von Braun (who would later
design NASA's Saturn V rocket) and his team of engineers. Their work centered
around the Redstone Jupiter-C rocket, which was derived from the V-2 missile
Germany had used against Britain during the war.

JPL's
role was to prepare the three upper stages for the launch vehicle, which
included the satellite itself. These used solid rocket motors the laboratory
had developed for the Army's Sergeant guided missile. JPL would also be
responsible for receiving and transmitting the orbiting spacecraft's
communications. In addition to JPL's involvement in the Orbiter program, the
laboratory's then-director, William Pickering, chaired the science committee on
satellite tracking for the U.S. launch effort overall.

The Navy's entry, called
Vanguard, had a competitive edge in that it was not derived from a ballistic
missile program -- its rocket was designed, from the ground up, for civilian
scientific purposes. The Army's Jupiter-C rocket had made its first
successful suborbital flight in 1956, so Army commanders were confident they
could be ready to launch a satellite fairly quickly. Nevertheless, the Navy's
program was chosen to launch a satellite for the IGY.

University of Iowa
physicist James Van Allen, whose instrument proposal had been chosen for the
Vanguard satellite, was concerned about development issues on the project.
Thus, he made sure his scientific instrument payload -- a cosmic ray detector
-- would fit either launch vehicle. Meanwhile, although their project was
officially mothballed, JPL engineers used a pre-existing rocket casing to
quietly build a flight-worthy satellite, just in case it might be needed.

The world changed on Oct. 4,
1957, when the Soviet Union launched a 23-inch (58-centimeter) metal sphere
called Sputnik. With that singular event, the space age had begun. The launch
resolved a key diplomatic uncertainty about the future of spaceflight,
establishing the right to orbit above any territory on the globe. The Russians
quickly followed up their first launch with a second Sputnik just a month
later. Under pressure to mount a U.S. response, the Eisenhower administration decided
a scheduled test flight of the Vanguard rocket, already being planned in
support of the IGY, would fit the bill. But when the Vanguard rocket was,
embarrassingly, destroyed during the launch attempt on Dec. 6, the administration
turned to the Army's program to save the country's reputation as a
technological leader.

Unbeknownst to JPL, von
Braun and his team had also been developing their own satellite, but after some
consideration, the Army decided that JPL would still provide the spacecraft.
The result of that fateful decision was that JPL's focus shifted permanently --
from rockets to what sits on top of them.

The Army team had its
orders to be ready for launch within 90 days. Thanks to its advance
preparation, 84 days later, its satellite stood on the launch pad at Cape
Canaveral Air Force Station in Florida.

The spacecraft was launched
at 10:48 p.m. EST on Friday, Jan. 31, 1958. An hour and a half later, a JPL
tracking station in California picked up its signal transmitted from orbit. In
keeping with the desire to portray the launch as the fulfillment of the U.S.
commitment under the International Geophysical Year, the announcement of its
success was made early the next morning at the National Academy of Sciences in
Washington, with Pickering, Van Allen and von Braun on hand to answer questions
from the media.

Following
the launch, the spacecraft was given its official name, Explorer 1. (In the
following decades, nearly a hundred spacecraft would be given the designation
"Explorer.") The satellite continued to transmit data for about four
months, until its batteries were exhausted, and it ceased operating on May 23,
1958.

Later that year, when the
National Aeronautics and Space Administration (NASA) was established by
Congress, Pickering and Caltech worked to shift JPL away from its defense work
to become part of the new agency. JPL remains a division of Caltech, which
manages the laboratory for NASA.

The
beginnings of U.S. space exploration were not without setbacks -- of the first
five Explorer satellites, two failed to reach orbit. But the three that made it
gave the world the first scientific discovery in space -- the Van Allen
radiation belts. These doughnut-shaped regions of high-energy particles, held
in place by Earth's magnetic field, may have been important in making Earth
habitable for life. Explorer 1, with Van Allen's cosmic ray detector on board,
was the first to detect this phenomenon, which is still being studied today.

In
advocating for a civilian space agency before Congress after the launch of
Explorer 1, Pickering drew on Van Allen's discovery, stating, "Dr. Van
Allen has given us some completely new information about the radiation present
in outer space....This is a rather dramatic example of a quite simple scientific
experiment which was our first step out into space."

Explorer 1 re-entered Earth's atmosphere and burned up
on March 31, 1970, after more than 58,000 orbits.

For
more information about Explorer 1 and the 60 years of U.S. space exploration
that have followed it, visit: